Auto merge of #144800 - Mark-Simulacrum:beta-next, r=Mark-Simulacrum

[beta] backports

Backport:

*  add unsupported_calling_conventions to lint list rust-lang/rust#144772
*  thread name in stack overflow message rust-lang/rust#144500
*  rustdoc: don't treat methods under const impls or traits as const rust-lang/rust#143381
* [beta] Clippy beta backport rust-lang/rust#144742

r? `@Mark-Simulacrum`

31 files changed, 329 insertions, 455 deletions

diff --git a/compiler/rustc_lint_defs/src/builtin.rs b/compiler/rustc_lint_defs/src/builtin.rs
index b0ea9689e50..731b5f77dd3 100644
--- a/compiler/rustc_lint_defs/src/builtin.rs
+++ b/compiler/rustc_lint_defs/src/builtin.rs
@@ -122,6 +122,7 @@ declare_lint_pass! {
         UNSAFE_OP_IN_UNSAFE_FN,
         UNSTABLE_NAME_COLLISIONS,
         UNSTABLE_SYNTAX_PRE_EXPANSION,
+        UNSUPPORTED_CALLING_CONVENTIONS,
         UNSUPPORTED_FN_PTR_CALLING_CONVENTIONS,
         UNUSED_ASSIGNMENTS,
         UNUSED_ASSOCIATED_TYPE_BOUNDS,
diff --git a/library/std/src/sys/pal/hermit/thread.rs b/library/std/src/sys/pal/hermit/thread.rs
index bb68a824fc3..0437a3c93e9 100644
--- a/library/std/src/sys/pal/hermit/thread.rs
+++ b/library/std/src/sys/pal/hermit/thread.rs
@@ -58,7 +58,11 @@ impl Thread {
         }
     }
 
-    pub unsafe fn new(stack: usize, p: Box<dyn FnOnce()>) -> io::Result<Thread> {
+    pub unsafe fn new(
+        stack: usize,
+        _name: Option<&str>,
+        p: Box<dyn FnOnce()>,
+    ) -> io::Result<Thread> {
         unsafe {
             Thread::new_with_coreid(stack, p, -1 /* = no specific core */)
         }
diff --git a/library/std/src/sys/pal/itron/thread.rs b/library/std/src/sys/pal/itron/thread.rs
index a974f4f17ae..c6cea9ab010 100644
--- a/library/std/src/sys/pal/itron/thread.rs
+++ b/library/std/src/sys/pal/itron/thread.rs
@@ -86,7 +86,11 @@ impl Thread {
     /// # Safety
     ///
     /// See `thread::Builder::spawn_unchecked` for safety requirements.
-    pub unsafe fn new(stack: usize, p: Box<dyn FnOnce()>) -> io::Result<Thread> {
+    pub unsafe fn new(
+        stack: usize,
+        _name: Option<&str>,
+        p: Box<dyn FnOnce()>,
+    ) -> io::Result<Thread> {
         let inner = Box::new(ThreadInner {
             start: UnsafeCell::new(ManuallyDrop::new(p)),
             lifecycle: AtomicUsize::new(LIFECYCLE_INIT),
diff --git a/library/std/src/sys/pal/sgx/thread.rs b/library/std/src/sys/pal/sgx/thread.rs
index 219ef1b7a98..a0b0d065962 100644
--- a/library/std/src/sys/pal/sgx/thread.rs
+++ b/library/std/src/sys/pal/sgx/thread.rs
@@ -96,7 +96,11 @@ pub mod wait_notify {
 
 impl Thread {
     // unsafe: see thread::Builder::spawn_unchecked for safety requirements
-    pub unsafe fn new(_stack: usize, p: Box<dyn FnOnce() + Send>) -> io::Result<Thread> {
+    pub unsafe fn new(
+        _stack: usize,
+        _name: Option<&str>,
+        p: Box<dyn FnOnce() + Send>,
+    ) -> io::Result<Thread> {
         let mut queue_lock = task_queue::lock();
         unsafe { usercalls::launch_thread()? };
         let (task, handle) = task_queue::Task::new(p);
diff --git a/library/std/src/sys/pal/teeos/thread.rs b/library/std/src/sys/pal/teeos/thread.rs
index e3b4908f858..a5b26ee961a 100644
--- a/library/std/src/sys/pal/teeos/thread.rs
+++ b/library/std/src/sys/pal/teeos/thread.rs
@@ -22,7 +22,11 @@ unsafe extern "C" {
 
 impl Thread {
     // unsafe: see thread::Builder::spawn_unchecked for safety requirements
-    pub unsafe fn new(stack: usize, p: Box<dyn FnOnce()>) -> io::Result<Thread> {
+    pub unsafe fn new(
+        stack: usize,
+        _name: Option<&str>,
+        p: Box<dyn FnOnce()>,
+    ) -> io::Result<Thread> {
         let p = Box::into_raw(Box::new(p));
         let mut native: libc::pthread_t = unsafe { mem::zeroed() };
         let mut attr: libc::pthread_attr_t = unsafe { mem::zeroed() };
diff --git a/library/std/src/sys/pal/uefi/thread.rs b/library/std/src/sys/pal/uefi/thread.rs
index 7d4006ff4b2..e1e66eaca1b 100644
--- a/library/std/src/sys/pal/uefi/thread.rs
+++ b/library/std/src/sys/pal/uefi/thread.rs
@@ -11,7 +11,11 @@ pub const DEFAULT_MIN_STACK_SIZE: usize = 64 * 1024;
 
 impl Thread {
     // unsafe: see thread::Builder::spawn_unchecked for safety requirements
-    pub unsafe fn new(_stack: usize, _p: Box<dyn FnOnce()>) -> io::Result<Thread> {
+    pub unsafe fn new(
+        _stack: usize,
+        _name: Option<&str>,
+        _p: Box<dyn FnOnce()>,
+    ) -> io::Result<Thread> {
         unsupported()
     }
 
diff --git a/library/std/src/sys/pal/unix/stack_overflow.rs b/library/std/src/sys/pal/unix/stack_overflow.rs
index a3be2cdf738..d89100e6919 100644
--- a/library/std/src/sys/pal/unix/stack_overflow.rs
+++ b/library/std/src/sys/pal/unix/stack_overflow.rs
@@ -8,8 +8,8 @@ pub struct Handler {
 }
 
 impl Handler {
-    pub unsafe fn new() -> Handler {
-        make_handler(false)
+    pub unsafe fn new(thread_name: Option<Box<str>>) -> Handler {
+        make_handler(false, thread_name)
     }
 
     fn null() -> Handler {
@@ -72,7 +72,6 @@ mod imp {
     use crate::sync::OnceLock;
     use crate::sync::atomic::{Atomic, AtomicBool, AtomicPtr, AtomicUsize, Ordering};
     use crate::sys::pal::unix::os;
-    use crate::thread::with_current_name;
     use crate::{io, mem, panic, ptr};
 
     // Signal handler for the SIGSEGV and SIGBUS handlers. We've got guard pages
@@ -158,13 +157,12 @@ mod imp {
                 if !NEED_ALTSTACK.load(Ordering::Relaxed) {
                     // haven't set up our sigaltstack yet
                     NEED_ALTSTACK.store(true, Ordering::Release);
-                    let handler = unsafe { make_handler(true) };
+                    let handler = unsafe { make_handler(true, None) };
                     MAIN_ALTSTACK.store(handler.data, Ordering::Relaxed);
                     mem::forget(handler);
 
                     if let Some(guard_page_range) = guard_page_range.take() {
-                        let thread_name = with_current_name(|name| name.map(Box::from));
-                        set_current_info(guard_page_range, thread_name);
+                        set_current_info(guard_page_range, Some(Box::from("main")));
                     }
                 }
 
@@ -230,14 +228,13 @@ mod imp {
     /// # Safety
     /// Mutates the alternate signal stack
     #[forbid(unsafe_op_in_unsafe_fn)]
-    pub unsafe fn make_handler(main_thread: bool) -> Handler {
+    pub unsafe fn make_handler(main_thread: bool, thread_name: Option<Box<str>>) -> Handler {
         if !NEED_ALTSTACK.load(Ordering::Acquire) {
             return Handler::null();
         }
 
         if !main_thread {
             if let Some(guard_page_range) = unsafe { current_guard() } {
-                let thread_name = with_current_name(|name| name.map(Box::from));
                 set_current_info(guard_page_range, thread_name);
             }
         }
@@ -634,7 +631,10 @@ mod imp {
 
     pub unsafe fn cleanup() {}
 
-    pub unsafe fn make_handler(_main_thread: bool) -> super::Handler {
+    pub unsafe fn make_handler(
+        _main_thread: bool,
+        _thread_name: Option<Box<str>>,
+    ) -> super::Handler {
         super::Handler::null()
     }
 
@@ -717,7 +717,10 @@ mod imp {
 
     pub unsafe fn cleanup() {}
 
-    pub unsafe fn make_handler(main_thread: bool) -> super::Handler {
+    pub unsafe fn make_handler(
+        main_thread: bool,
+        _thread_name: Option<Box<str>>,
+    ) -> super::Handler {
         if !main_thread {
             reserve_stack();
         }
diff --git a/library/std/src/sys/pal/unix/thread.rs b/library/std/src/sys/pal/unix/thread.rs
index d8b189413f4..5f2b81b0588 100644
--- a/library/std/src/sys/pal/unix/thread.rs
+++ b/library/std/src/sys/pal/unix/thread.rs
@@ -22,6 +22,11 @@ pub const DEFAULT_MIN_STACK_SIZE: usize = 256 * 1024;
 #[cfg(any(target_os = "espidf", target_os = "nuttx"))]
 pub const DEFAULT_MIN_STACK_SIZE: usize = 0; // 0 indicates that the stack size configured in the ESP-IDF/NuttX menuconfig system should be used
 
+struct ThreadData {
+    name: Option<Box<str>>,
+    f: Box<dyn FnOnce()>,
+}
+
 pub struct Thread {
     id: libc::pthread_t,
 }
@@ -34,8 +39,12 @@ unsafe impl Sync for Thread {}
 impl Thread {
     // unsafe: see thread::Builder::spawn_unchecked for safety requirements
     #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
-    pub unsafe fn new(stack: usize, p: Box<dyn FnOnce()>) -> io::Result<Thread> {
-        let p = Box::into_raw(Box::new(p));
+    pub unsafe fn new(
+        stack: usize,
+        name: Option<&str>,
+        f: Box<dyn FnOnce()>,
+    ) -> io::Result<Thread> {
+        let data = Box::into_raw(Box::new(ThreadData { name: name.map(Box::from), f }));
         let mut native: libc::pthread_t = mem::zeroed();
         let mut attr: mem::MaybeUninit<libc::pthread_attr_t> = mem::MaybeUninit::uninit();
         assert_eq!(libc::pthread_attr_init(attr.as_mut_ptr()), 0);
@@ -73,7 +82,7 @@ impl Thread {
             };
         }
 
-        let ret = libc::pthread_create(&mut native, attr.as_ptr(), thread_start, p as *mut _);
+        let ret = libc::pthread_create(&mut native, attr.as_ptr(), thread_start, data as *mut _);
         // Note: if the thread creation fails and this assert fails, then p will
         // be leaked. However, an alternative design could cause double-free
         // which is clearly worse.
@@ -82,19 +91,20 @@ impl Thread {
         return if ret != 0 {
             // The thread failed to start and as a result p was not consumed. Therefore, it is
             // safe to reconstruct the box so that it gets deallocated.
-            drop(Box::from_raw(p));
+            drop(Box::from_raw(data));
             Err(io::Error::from_raw_os_error(ret))
         } else {
             Ok(Thread { id: native })
         };
 
-        extern "C" fn thread_start(main: *mut libc::c_void) -> *mut libc::c_void {
+        extern "C" fn thread_start(data: *mut libc::c_void) -> *mut libc::c_void {
             unsafe {
+                let data = Box::from_raw(data as *mut ThreadData);
                 // Next, set up our stack overflow handler which may get triggered if we run
                 // out of stack.
-                let _handler = stack_overflow::Handler::new();
+                let _handler = stack_overflow::Handler::new(data.name);
                 // Finally, let's run some code.
-                Box::from_raw(main as *mut Box<dyn FnOnce()>)();
+                (data.f)();
             }
             ptr::null_mut()
         }
diff --git a/library/std/src/sys/pal/unsupported/thread.rs b/library/std/src/sys/pal/unsupported/thread.rs
index 89f8bad7026..51b4916fcda 100644
--- a/library/std/src/sys/pal/unsupported/thread.rs
+++ b/library/std/src/sys/pal/unsupported/thread.rs
@@ -10,7 +10,11 @@ pub const DEFAULT_MIN_STACK_SIZE: usize = 64 * 1024;
 
 impl Thread {
     // unsafe: see thread::Builder::spawn_unchecked for safety requirements
-    pub unsafe fn new(_stack: usize, _p: Box<dyn FnOnce()>) -> io::Result<Thread> {
+    pub unsafe fn new(
+        _stack: usize,
+        _name: Option<&str>,
+        _p: Box<dyn FnOnce()>,
+    ) -> io::Result<Thread> {
         unsupported()
     }
 
diff --git a/library/std/src/sys/pal/wasi/thread.rs b/library/std/src/sys/pal/wasi/thread.rs
index cc569bb3daf..52abd7b8f78 100644
--- a/library/std/src/sys/pal/wasi/thread.rs
+++ b/library/std/src/sys/pal/wasi/thread.rs
@@ -73,7 +73,7 @@ impl Thread {
     // unsafe: see thread::Builder::spawn_unchecked for safety requirements
     cfg_if::cfg_if! {
         if #[cfg(target_feature = "atomics")] {
-            pub unsafe fn new(stack: usize, p: Box<dyn FnOnce()>) -> io::Result<Thread> {
+            pub unsafe fn new(stack: usize, _name: Option<&str>, p: Box<dyn FnOnce()>) -> io::Result<Thread> {
                 let p = Box::into_raw(Box::new(p));
                 let mut native: libc::pthread_t = unsafe { mem::zeroed() };
                 let mut attr: libc::pthread_attr_t = unsafe { mem::zeroed() };
@@ -120,7 +120,7 @@ impl Thread {
                 }
             }
         } else {
-            pub unsafe fn new(_stack: usize, _p: Box<dyn FnOnce()>) -> io::Result<Thread> {
+            pub unsafe fn new(_stack: usize, _name: Option<&str>, _p: Box<dyn FnOnce()>) -> io::Result<Thread> {
                 crate::sys::unsupported()
             }
         }
diff --git a/library/std/src/sys/pal/wasm/atomics/thread.rs b/library/std/src/sys/pal/wasm/atomics/thread.rs
index dd5aff391fd..5d5c40f5568 100644
--- a/library/std/src/sys/pal/wasm/atomics/thread.rs
+++ b/library/std/src/sys/pal/wasm/atomics/thread.rs
@@ -10,7 +10,11 @@ pub const DEFAULT_MIN_STACK_SIZE: usize = 1024 * 1024;
 
 impl Thread {
     // unsafe: see thread::Builder::spawn_unchecked for safety requirements
-    pub unsafe fn new(_stack: usize, _p: Box<dyn FnOnce()>) -> io::Result<Thread> {
+    pub unsafe fn new(
+        _stack: usize,
+        _name: Option<&str>,
+        _p: Box<dyn FnOnce()>,
+    ) -> io::Result<Thread> {
         unsupported()
     }
 
diff --git a/library/std/src/sys/pal/windows/thread.rs b/library/std/src/sys/pal/windows/thread.rs
index 45e52cf4d04..66891ea10b2 100644
--- a/library/std/src/sys/pal/windows/thread.rs
+++ b/library/std/src/sys/pal/windows/thread.rs
@@ -20,7 +20,11 @@ pub struct Thread {
 impl Thread {
     // unsafe: see thread::Builder::spawn_unchecked for safety requirements
     #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
-    pub unsafe fn new(stack: usize, p: Box<dyn FnOnce()>) -> io::Result<Thread> {
+    pub unsafe fn new(
+        stack: usize,
+        _name: Option<&str>,
+        p: Box<dyn FnOnce()>,
+    ) -> io::Result<Thread> {
         let p = Box::into_raw(Box::new(p));
 
         // CreateThread rounds up values for the stack size to the nearest page size (at least 4kb).
diff --git a/library/std/src/sys/pal/xous/thread.rs b/library/std/src/sys/pal/xous/thread.rs
index 0ebb46dc19f..a2a93e5ecad 100644
--- a/library/std/src/sys/pal/xous/thread.rs
+++ b/library/std/src/sys/pal/xous/thread.rs
@@ -20,7 +20,11 @@ pub const GUARD_PAGE_SIZE: usize = 4096;
 
 impl Thread {
     // unsafe: see thread::Builder::spawn_unchecked for safety requirements
-    pub unsafe fn new(stack: usize, p: Box<dyn FnOnce()>) -> io::Result<Thread> {
+    pub unsafe fn new(
+        stack: usize,
+        _name: Option<&str>,
+        p: Box<dyn FnOnce()>,
+    ) -> io::Result<Thread> {
         let p = Box::into_raw(Box::new(p));
         let mut stack_size = crate::cmp::max(stack, MIN_STACK_SIZE);
 
diff --git a/library/std/src/thread/mod.rs b/library/std/src/thread/mod.rs
index 26b2fb44724..491e3ac1d46 100644
--- a/library/std/src/thread/mod.rs
+++ b/library/std/src/thread/mod.rs
@@ -595,7 +595,7 @@ impl Builder {
             // Similarly, the `sys` implementation must guarantee that no references to the closure
             // exist after the thread has terminated, which is signaled by `Thread::join`
             // returning.
-            native: unsafe { imp::Thread::new(stack_size, main)? },
+            native: unsafe { imp::Thread::new(stack_size, my_thread.name(), main)? },
             thread: my_thread,
             packet: my_packet,
         })
diff --git a/src/librustdoc/clean/types.rs b/src/librustdoc/clean/types.rs
index 0aedc7f5219..567ceec6dc3 100644
--- a/src/librustdoc/clean/types.rs
+++ b/src/librustdoc/clean/types.rs
@@ -647,7 +647,20 @@ impl Item {
         ) -> hir::FnHeader {
             let sig = tcx.fn_sig(def_id).skip_binder();
             let constness = if tcx.is_const_fn(def_id) {
-                hir::Constness::Const
+                // rustc's `is_const_fn` returns `true` for associated functions that have an `impl const` parent
+                // or that have a `#[const_trait]` parent. Do not display those as `const` in rustdoc because we
+                // won't be printing correct syntax plus the syntax is unstable.
+                match tcx.opt_associated_item(def_id) {
+                    Some(ty::AssocItem {
+                        container: ty::AssocItemContainer::Impl,
+                        trait_item_def_id: Some(_),
+                        ..
+                    })
+                    | Some(ty::AssocItem { container: ty::AssocItemContainer::Trait, .. }) => {
+                        hir::Constness::NotConst
+                    }
+                    None | Some(_) => hir::Constness::Const,
+                }
             } else {
                 hir::Constness::NotConst
             };
diff --git a/src/tools/clippy/clippy_lints/src/format_args.rs b/src/tools/clippy/clippy_lints/src/format_args.rs
index 0c39aae9ca9..fd1e6700698 100644
--- a/src/tools/clippy/clippy_lints/src/format_args.rs
+++ b/src/tools/clippy/clippy_lints/src/format_args.rs
@@ -163,7 +163,7 @@ declare_clippy_lint! {
     /// nothing will be suggested, e.g. `println!("{0}={1}", var, 1+2)`.
     #[clippy::version = "1.66.0"]
     pub UNINLINED_FORMAT_ARGS,
-    style,
+    pedantic,
     "using non-inlined variables in `format!` calls"
 }
 
diff --git a/src/tools/clippy/clippy_lints/src/methods/manual_is_variant_and.rs b/src/tools/clippy/clippy_lints/src/methods/manual_is_variant_and.rs
index 4a61c223d2c..40aad03960c 100644
--- a/src/tools/clippy/clippy_lints/src/methods/manual_is_variant_and.rs
+++ b/src/tools/clippy/clippy_lints/src/methods/manual_is_variant_and.rs
@@ -1,22 +1,18 @@
 use clippy_utils::diagnostics::span_lint_and_sugg;
-use clippy_utils::get_parent_expr;
 use clippy_utils::msrvs::{self, Msrv};
-use clippy_utils::source::{snippet, snippet_opt};
+use clippy_utils::source::snippet;
 use clippy_utils::ty::is_type_diagnostic_item;
 use rustc_errors::Applicability;
-use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res};
-use rustc_hir::{BinOpKind, Expr, ExprKind, QPath};
 use rustc_lint::LateContext;
-use rustc_middle::ty;
-use rustc_span::{BytePos, Span, sym};
+use rustc_span::{Span, sym};
 
 use super::MANUAL_IS_VARIANT_AND;
 
-pub(super) fn check(
+pub(super) fn check<'tcx>(
     cx: &LateContext<'_>,
-    expr: &Expr<'_>,
-    map_recv: &Expr<'_>,
-    map_arg: &Expr<'_>,
+    expr: &'tcx rustc_hir::Expr<'_>,
+    map_recv: &'tcx rustc_hir::Expr<'_>,
+    map_arg: &'tcx rustc_hir::Expr<'_>,
     map_span: Span,
     msrv: Msrv,
 ) {
@@ -61,57 +57,3 @@ pub(super) fn check(
         Applicability::MachineApplicable,
     );
 }
-
-fn emit_lint(cx: &LateContext<'_>, op: BinOpKind, parent: &Expr<'_>, method_span: Span, is_option: bool) {
-    if let Some(before_map_snippet) = snippet_opt(cx, parent.span.with_hi(method_span.lo()))
-        && let Some(after_map_snippet) = snippet_opt(cx, method_span.with_lo(method_span.lo() + BytePos(3)))
-    {
-        span_lint_and_sugg(
-            cx,
-            MANUAL_IS_VARIANT_AND,
-            parent.span,
-            format!(
-                "called `.map() {}= {}()`",
-                if op == BinOpKind::Eq { '=' } else { '!' },
-                if is_option { "Some" } else { "Ok" },
-            ),
-            "use",
-            if is_option && op == BinOpKind::Ne {
-                format!("{before_map_snippet}is_none_or{after_map_snippet}",)
-            } else {
-                format!(
-                    "{}{before_map_snippet}{}{after_map_snippet}",
-                    if op == BinOpKind::Eq { "" } else { "!" },
-                    if is_option { "is_some_and" } else { "is_ok_and" },
-                )
-            },
-            Applicability::MachineApplicable,
-        );
-    }
-}
-
-pub(super) fn check_map(cx: &LateContext<'_>, expr: &Expr<'_>) {
-    if let Some(parent_expr) = get_parent_expr(cx, expr)
-        && let ExprKind::Binary(op, left, right) = parent_expr.kind
-        && matches!(op.node, BinOpKind::Eq | BinOpKind::Ne)
-        && op.span.eq_ctxt(expr.span)
-    {
-        // Check `left` and `right` expression in any order, and for `Option` and `Result`
-        for (expr1, expr2) in [(left, right), (right, left)] {
-            for item in [sym::Option, sym::Result] {
-                if let ExprKind::Call(call, ..) = expr1.kind
-                    && let ExprKind::Path(QPath::Resolved(_, path)) = call.kind
-                    && let Res::Def(DefKind::Ctor(CtorOf::Variant, CtorKind::Fn), _) = path.res
-                    && let ty = cx.typeck_results().expr_ty(expr1)
-                    && let ty::Adt(adt, args) = ty.kind()
-                    && cx.tcx.is_diagnostic_item(item, adt.did())
-                    && args.type_at(0).is_bool()
-                    && let ExprKind::MethodCall(_, recv, _, span) = expr2.kind
-                    && is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(recv), item)
-                {
-                    return emit_lint(cx, op.node, parent_expr, span, item == sym::Option);
-                }
-            }
-        }
-    }
-}
diff --git a/src/tools/clippy/clippy_lints/src/methods/mod.rs b/src/tools/clippy/clippy_lints/src/methods/mod.rs
index 347960e0003..6d3f59520a2 100644
--- a/src/tools/clippy/clippy_lints/src/methods/mod.rs
+++ b/src/tools/clippy/clippy_lints/src/methods/mod.rs
@@ -5242,7 +5242,6 @@ impl Methods {
                         unused_enumerate_index::check(cx, expr, recv, m_arg);
                         map_clone::check(cx, expr, recv, m_arg, self.msrv);
                         map_with_unused_argument_over_ranges::check(cx, expr, recv, m_arg, self.msrv, span);
-                        manual_is_variant_and::check_map(cx, expr);
                         match method_call(recv) {
                             Some((map_name @ (sym::iter | sym::into_iter), recv2, _, _, _)) => {
                                 iter_kv_map::check(cx, map_name, expr, recv2, m_arg, self.msrv);
diff --git a/src/tools/clippy/clippy_lints/src/methods/return_and_then.rs b/src/tools/clippy/clippy_lints/src/methods/return_and_then.rs
index df8544f9220..91643b0dfef 100644
--- a/src/tools/clippy/clippy_lints/src/methods/return_and_then.rs
+++ b/src/tools/clippy/clippy_lints/src/methods/return_and_then.rs
@@ -9,7 +9,7 @@ use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::source::{indent_of, reindent_multiline, snippet_with_applicability};
 use clippy_utils::ty::get_type_diagnostic_name;
 use clippy_utils::visitors::for_each_unconsumed_temporary;
-use clippy_utils::{get_parent_expr, peel_blocks};
+use clippy_utils::{is_expr_final_block_expr, peel_blocks};
 
 use super::RETURN_AND_THEN;
 
@@ -21,7 +21,7 @@ pub(super) fn check<'tcx>(
     recv: &'tcx hir::Expr<'tcx>,
     arg: &'tcx hir::Expr<'_>,
 ) {
-    if cx.tcx.hir_get_fn_id_for_return_block(expr.hir_id).is_none() {
+    if !is_expr_final_block_expr(cx.tcx, expr) {
         return;
     }
 
@@ -55,24 +55,12 @@ pub(super) fn check<'tcx>(
         None => &body_snip,
     };
 
-    // If suggestion is going to get inserted as part of a `return` expression, it must be blockified.
-    let sugg = if let Some(parent_expr) = get_parent_expr(cx, expr) {
-        let base_indent = indent_of(cx, parent_expr.span);
-        let inner_indent = base_indent.map(|i| i + 4);
-        format!(
-            "{}\n{}\n{}",
-            reindent_multiline(&format!("{{\nlet {arg_snip} = {recv_snip}?;"), true, inner_indent),
-            reindent_multiline(inner, false, inner_indent),
-            reindent_multiline("}", false, base_indent),
-        )
-    } else {
-        format!(
-            "let {} = {}?;\n{}",
-            arg_snip,
-            recv_snip,
-            reindent_multiline(inner, false, indent_of(cx, expr.span))
-        )
-    };
+    let sugg = format!(
+        "let {} = {}?;\n{}",
+        arg_snip,
+        recv_snip,
+        reindent_multiline(inner, false, indent_of(cx, expr.span))
+    );
 
     span_lint_and_sugg(
         cx,
diff --git a/src/tools/clippy/clippy_lints/src/methods/swap_with_temporary.rs b/src/tools/clippy/clippy_lints/src/methods/swap_with_temporary.rs
index de729fb343a..e378cbd6ae0 100644
--- a/src/tools/clippy/clippy_lints/src/methods/swap_with_temporary.rs
+++ b/src/tools/clippy/clippy_lints/src/methods/swap_with_temporary.rs
@@ -4,6 +4,7 @@ use rustc_ast::BorrowKind;
 use rustc_errors::{Applicability, Diag};
 use rustc_hir::{Expr, ExprKind, Node, QPath};
 use rustc_lint::LateContext;
+use rustc_middle::ty::adjustment::Adjust;
 use rustc_span::sym;
 
 use super::SWAP_WITH_TEMPORARY;
@@ -11,12 +12,12 @@ use super::SWAP_WITH_TEMPORARY;
 const MSG_TEMPORARY: &str = "this expression returns a temporary value";
 const MSG_TEMPORARY_REFMUT: &str = "this is a mutable reference to a temporary value";
 
-pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, func: &Expr<'_>, args: &[Expr<'_>]) {
+pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'_>, func: &Expr<'_>, args: &'tcx [Expr<'_>]) {
     if let ExprKind::Path(QPath::Resolved(_, func_path)) = func.kind
         && let Some(func_def_id) = func_path.res.opt_def_id()
         && cx.tcx.is_diagnostic_item(sym::mem_swap, func_def_id)
     {
-        match (ArgKind::new(&args[0]), ArgKind::new(&args[1])) {
+        match (ArgKind::new(cx, &args[0]), ArgKind::new(cx, &args[1])) {
             (ArgKind::RefMutToTemp(left_temp), ArgKind::RefMutToTemp(right_temp)) => {
                 emit_lint_useless(cx, expr, &args[0], &args[1], left_temp, right_temp);
             },
@@ -28,10 +29,10 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, func: &Expr<'_>, args
 }
 
 enum ArgKind<'tcx> {
-    // Mutable reference to a place, coming from a macro
-    RefMutToPlaceAsMacro(&'tcx Expr<'tcx>),
-    // Place behind a mutable reference
-    RefMutToPlace(&'tcx Expr<'tcx>),
+    // Mutable reference to a place, coming from a macro, and number of dereferences to use
+    RefMutToPlaceAsMacro(&'tcx Expr<'tcx>, usize),
+    // Place behind a mutable reference, and number of dereferences to use
+    RefMutToPlace(&'tcx Expr<'tcx>, usize),
     // Temporary value behind a mutable reference
     RefMutToTemp(&'tcx Expr<'tcx>),
     // Any other case
@@ -39,13 +40,29 @@ enum ArgKind<'tcx> {
 }
 
 impl<'tcx> ArgKind<'tcx> {
-    fn new(arg: &'tcx Expr<'tcx>) -> Self {
-        if let ExprKind::AddrOf(BorrowKind::Ref, _, target) = arg.kind {
-            if target.is_syntactic_place_expr() {
+    /// Build a new `ArgKind` from `arg`. There must be no false positive when returning a
+    /// `ArgKind::RefMutToTemp` variant, as this may cause a spurious lint to be emitted.
+    fn new(cx: &LateContext<'tcx>, arg: &'tcx Expr<'tcx>) -> Self {
+        if let ExprKind::AddrOf(BorrowKind::Ref, _, target) = arg.kind
+            && let adjustments = cx.typeck_results().expr_adjustments(arg)
+            && adjustments
+                .first()
+                .is_some_and(|adj| matches!(adj.kind, Adjust::Deref(None)))
+            && adjustments
+                .last()
+                .is_some_and(|adj| matches!(adj.kind, Adjust::Borrow(_)))
+        {
+            let extra_derefs = adjustments[1..adjustments.len() - 1]
+                .iter()
+                .filter(|adj| matches!(adj.kind, Adjust::Deref(_)))
+                .count();
+            // If a deref is used, `arg` might be a place expression. For example, a mutex guard
+            // would dereference into the mutex content which is probably not temporary.
+            if target.is_syntactic_place_expr() || extra_derefs > 0 {
                 if arg.span.from_expansion() {
-                    ArgKind::RefMutToPlaceAsMacro(arg)
+                    ArgKind::RefMutToPlaceAsMacro(arg, extra_derefs)
                 } else {
-                    ArgKind::RefMutToPlace(target)
+                    ArgKind::RefMutToPlace(target, extra_derefs)
                 }
             } else {
                 ArgKind::RefMutToTemp(target)
@@ -106,10 +123,15 @@ fn emit_lint_assign(cx: &LateContext<'_>, expr: &Expr<'_>, target: &ArgKind<'_>,
                 let mut applicability = Applicability::MachineApplicable;
                 let ctxt = expr.span.ctxt();
                 let assign_target = match target {
-                    ArgKind::Expr(target) | ArgKind::RefMutToPlaceAsMacro(target) => {
-                        Sugg::hir_with_context(cx, target, ctxt, "_", &mut applicability).deref()
-                    },
-                    ArgKind::RefMutToPlace(target) => Sugg::hir_with_context(cx, target, ctxt, "_", &mut applicability),
+                    ArgKind::Expr(target) => Sugg::hir_with_context(cx, target, ctxt, "_", &mut applicability).deref(),
+                    ArgKind::RefMutToPlaceAsMacro(arg, derefs) => (0..*derefs).fold(
+                        Sugg::hir_with_context(cx, arg, ctxt, "_", &mut applicability).deref(),
+                        |sugg, _| sugg.deref(),
+                    ),
+                    ArgKind::RefMutToPlace(target, derefs) => (0..*derefs).fold(
+                        Sugg::hir_with_context(cx, target, ctxt, "_", &mut applicability),
+                        |sugg, _| sugg.deref(),
+                    ),
                     ArgKind::RefMutToTemp(_) => unreachable!(),
                 };
                 let assign_source = Sugg::hir_with_context(cx, temp, ctxt, "_", &mut applicability);
diff --git a/src/tools/clippy/tests/ui/manual_is_variant_and.fixed b/src/tools/clippy/tests/ui/manual_is_variant_and.fixed
index 18a72188ab5..c9c184561dd 100644
--- a/src/tools/clippy/tests/ui/manual_is_variant_and.fixed
+++ b/src/tools/clippy/tests/ui/manual_is_variant_and.fixed
@@ -4,44 +4,6 @@
 #[macro_use]
 extern crate option_helpers;
 
-struct Foo<T>(T);
-
-impl<T> Foo<T> {
-    fn map<F: FnMut(T) -> bool>(self, mut f: F) -> Option<bool> {
-        Some(f(self.0))
-    }
-}
-
-fn foo() -> Option<bool> {
-    Some(true)
-}
-
-macro_rules! some_true {
-    () => {
-        Some(true)
-    };
-}
-macro_rules! some_false {
-    () => {
-        Some(false)
-    };
-}
-
-macro_rules! mac {
-    (some $e:expr) => {
-        Some($e)
-    };
-    (some_map $e:expr) => {
-        Some($e).map(|x| x % 2 == 0)
-    };
-    (map $e:expr) => {
-        $e.map(|x| x % 2 == 0)
-    };
-    (eq $a:expr, $b:expr) => {
-        $a == $b
-    };
-}
-
 #[rustfmt::skip]
 fn option_methods() {
     let opt = Some(1);
@@ -59,15 +21,6 @@ fn option_methods() {
     let _ = opt
         .is_some_and(|x| x > 1);
 
-    let _ = Some(2).is_some_and(|x| x % 2 == 0);
-    //~^ manual_is_variant_and
-    let _ = Some(2).is_none_or(|x| x % 2 == 0);
-    //~^ manual_is_variant_and
-    let _ = Some(2).is_some_and(|x| x % 2 == 0);
-    //~^ manual_is_variant_and
-    let _ = Some(2).is_none_or(|x| x % 2 == 0);
-    //~^ manual_is_variant_and
-
     // won't fix because the return type of the closure is not `bool`
     let _ = opt.map(|x| x + 1).unwrap_or_default();
 
@@ -75,14 +28,6 @@ fn option_methods() {
     let _ = opt2.is_some_and(char::is_alphanumeric); // should lint
     //~^ manual_is_variant_and
     let _ = opt_map!(opt2, |x| x == 'a').unwrap_or_default(); // should not lint
-
-    // Should not lint.
-    let _ = Foo::<u32>(0).map(|x| x % 2 == 0) == Some(true);
-    let _ = Some(2).map(|x| x % 2 == 0) != foo();
-    let _ = mac!(eq Some(2).map(|x| x % 2 == 0), Some(true));
-    let _ = mac!(some 2).map(|x| x % 2 == 0) == Some(true);
-    let _ = mac!(some_map 2) == Some(true);
-    let _ = mac!(map Some(2)) == Some(true);
 }
 
 #[rustfmt::skip]
@@ -96,13 +41,6 @@ fn result_methods() {
     });
     let _ = res.is_ok_and(|x| x > 1);
 
-    let _ = Ok::<usize, ()>(2).is_ok_and(|x| x % 2 == 0);
-    //~^ manual_is_variant_and
-    let _ = !Ok::<usize, ()>(2).is_ok_and(|x| x % 2 == 0);
-    //~^ manual_is_variant_and
-    let _ = !Ok::<usize, ()>(2).is_ok_and(|x| x % 2 == 0);
-    //~^ manual_is_variant_and
-
     // won't fix because the return type of the closure is not `bool`
     let _ = res.map(|x| x + 1).unwrap_or_default();
 
diff --git a/src/tools/clippy/tests/ui/manual_is_variant_and.rs b/src/tools/clippy/tests/ui/manual_is_variant_and.rs
index a92f7c04369..52c7b56804c 100644
--- a/src/tools/clippy/tests/ui/manual_is_variant_and.rs
+++ b/src/tools/clippy/tests/ui/manual_is_variant_and.rs
@@ -4,44 +4,6 @@
 #[macro_use]
 extern crate option_helpers;
 
-struct Foo<T>(T);
-
-impl<T> Foo<T> {
-    fn map<F: FnMut(T) -> bool>(self, mut f: F) -> Option<bool> {
-        Some(f(self.0))
-    }
-}
-
-fn foo() -> Option<bool> {
-    Some(true)
-}
-
-macro_rules! some_true {
-    () => {
-        Some(true)
-    };
-}
-macro_rules! some_false {
-    () => {
-        Some(false)
-    };
-}
-
-macro_rules! mac {
-    (some $e:expr) => {
-        Some($e)
-    };
-    (some_map $e:expr) => {
-        Some($e).map(|x| x % 2 == 0)
-    };
-    (map $e:expr) => {
-        $e.map(|x| x % 2 == 0)
-    };
-    (eq $a:expr, $b:expr) => {
-        $a == $b
-    };
-}
-
 #[rustfmt::skip]
 fn option_methods() {
     let opt = Some(1);
@@ -65,15 +27,6 @@ fn option_methods() {
         //~^ manual_is_variant_and
         .unwrap_or_default();
 
-    let _ = Some(2).map(|x| x % 2 == 0) == Some(true);
-    //~^ manual_is_variant_and
-    let _ = Some(2).map(|x| x % 2 == 0) != Some(true);
-    //~^ manual_is_variant_and
-    let _ = Some(2).map(|x| x % 2 == 0) == some_true!();
-    //~^ manual_is_variant_and
-    let _ = Some(2).map(|x| x % 2 == 0) != some_false!();
-    //~^ manual_is_variant_and
-
     // won't fix because the return type of the closure is not `bool`
     let _ = opt.map(|x| x + 1).unwrap_or_default();
 
@@ -81,14 +34,6 @@ fn option_methods() {
     let _ = opt2.map(char::is_alphanumeric).unwrap_or_default(); // should lint
     //~^ manual_is_variant_and
     let _ = opt_map!(opt2, |x| x == 'a').unwrap_or_default(); // should not lint
-
-    // Should not lint.
-    let _ = Foo::<u32>(0).map(|x| x % 2 == 0) == Some(true);
-    let _ = Some(2).map(|x| x % 2 == 0) != foo();
-    let _ = mac!(eq Some(2).map(|x| x % 2 == 0), Some(true));
-    let _ = mac!(some 2).map(|x| x % 2 == 0) == Some(true);
-    let _ = mac!(some_map 2) == Some(true);
-    let _ = mac!(map Some(2)) == Some(true);
 }
 
 #[rustfmt::skip]
@@ -105,13 +50,6 @@ fn result_methods() {
     //~^ manual_is_variant_and
         .unwrap_or_default();
 
-    let _ = Ok::<usize, ()>(2).map(|x| x % 2 == 0) == Ok(true);
-    //~^ manual_is_variant_and
-    let _ = Ok::<usize, ()>(2).map(|x| x % 2 == 0) != Ok(true);
-    //~^ manual_is_variant_and
-    let _ = Ok::<usize, ()>(2).map(|x| x % 2 == 0) != Ok(true);
-    //~^ manual_is_variant_and
-
     // won't fix because the return type of the closure is not `bool`
     let _ = res.map(|x| x + 1).unwrap_or_default();
 
diff --git a/src/tools/clippy/tests/ui/manual_is_variant_and.stderr b/src/tools/clippy/tests/ui/manual_is_variant_and.stderr
index 1fb437a8bc7..a4fa500580d 100644
--- a/src/tools/clippy/tests/ui/manual_is_variant_and.stderr
+++ b/src/tools/clippy/tests/ui/manual_is_variant_and.stderr
@@ -1,5 +1,5 @@
 error: called `map(<f>).unwrap_or_default()` on an `Option` value
-  --> tests/ui/manual_is_variant_and.rs:51:17
+  --> tests/ui/manual_is_variant_and.rs:13:17
    |
 LL |       let _ = opt.map(|x| x > 1)
    |  _________________^
@@ -11,7 +11,7 @@ LL | |         .unwrap_or_default();
    = help: to override `-D warnings` add `#[allow(clippy::manual_is_variant_and)]`
 
 error: called `map(<f>).unwrap_or_default()` on an `Option` value
-  --> tests/ui/manual_is_variant_and.rs:56:17
+  --> tests/ui/manual_is_variant_and.rs:18:17
    |
 LL |       let _ = opt.map(|x| {
    |  _________________^
@@ -30,13 +30,13 @@ LL ~     });
    |
 
 error: called `map(<f>).unwrap_or_default()` on an `Option` value
-  --> tests/ui/manual_is_variant_and.rs:61:17
+  --> tests/ui/manual_is_variant_and.rs:23:17
    |
 LL |     let _ = opt.map(|x| x > 1).unwrap_or_default();
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use: `is_some_and(|x| x > 1)`
 
 error: called `map(<f>).unwrap_or_default()` on an `Option` value
-  --> tests/ui/manual_is_variant_and.rs:64:10
+  --> tests/ui/manual_is_variant_and.rs:26:10
    |
 LL |           .map(|x| x > 1)
    |  __________^
@@ -44,38 +44,14 @@ LL | |
 LL | |         .unwrap_or_default();
    | |____________________________^ help: use: `is_some_and(|x| x > 1)`
 
-error: called `.map() == Some()`
-  --> tests/ui/manual_is_variant_and.rs:68:13
-   |
-LL |     let _ = Some(2).map(|x| x % 2 == 0) == Some(true);
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use: `Some(2).is_some_and(|x| x % 2 == 0)`
-
-error: called `.map() != Some()`
-  --> tests/ui/manual_is_variant_and.rs:70:13
-   |
-LL |     let _ = Some(2).map(|x| x % 2 == 0) != Some(true);
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use: `Some(2).is_none_or(|x| x % 2 == 0)`
-
-error: called `.map() == Some()`
-  --> tests/ui/manual_is_variant_and.rs:72:13
-   |
-LL |     let _ = Some(2).map(|x| x % 2 == 0) == some_true!();
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use: `Some(2).is_some_and(|x| x % 2 == 0)`
-
-error: called `.map() != Some()`
-  --> tests/ui/manual_is_variant_and.rs:74:13
-   |
-LL |     let _ = Some(2).map(|x| x % 2 == 0) != some_false!();
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use: `Some(2).is_none_or(|x| x % 2 == 0)`
-
 error: called `map(<f>).unwrap_or_default()` on an `Option` value
-  --> tests/ui/manual_is_variant_and.rs:81:18
+  --> tests/ui/manual_is_variant_and.rs:34:18
    |
 LL |     let _ = opt2.map(char::is_alphanumeric).unwrap_or_default(); // should lint
    |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use: `is_some_and(char::is_alphanumeric)`
 
 error: called `map(<f>).unwrap_or_default()` on a `Result` value
-  --> tests/ui/manual_is_variant_and.rs:99:17
+  --> tests/ui/manual_is_variant_and.rs:44:17
    |
 LL |       let _ = res.map(|x| {
    |  _________________^
@@ -94,7 +70,7 @@ LL ~     });
    |
 
 error: called `map(<f>).unwrap_or_default()` on a `Result` value
-  --> tests/ui/manual_is_variant_and.rs:104:17
+  --> tests/ui/manual_is_variant_and.rs:49:17
    |
 LL |       let _ = res.map(|x| x > 1)
    |  _________________^
@@ -102,29 +78,11 @@ LL | |
 LL | |         .unwrap_or_default();
    | |____________________________^ help: use: `is_ok_and(|x| x > 1)`
 
-error: called `.map() == Ok()`
-  --> tests/ui/manual_is_variant_and.rs:108:13
-   |
-LL |     let _ = Ok::<usize, ()>(2).map(|x| x % 2 == 0) == Ok(true);
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use: `Ok::<usize, ()>(2).is_ok_and(|x| x % 2 == 0)`
-
-error: called `.map() != Ok()`
-  --> tests/ui/manual_is_variant_and.rs:110:13
-   |
-LL |     let _ = Ok::<usize, ()>(2).map(|x| x % 2 == 0) != Ok(true);
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use: `!Ok::<usize, ()>(2).is_ok_and(|x| x % 2 == 0)`
-
-error: called `.map() != Ok()`
-  --> tests/ui/manual_is_variant_and.rs:112:13
-   |
-LL |     let _ = Ok::<usize, ()>(2).map(|x| x % 2 == 0) != Ok(true);
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use: `!Ok::<usize, ()>(2).is_ok_and(|x| x % 2 == 0)`
-
 error: called `map(<f>).unwrap_or_default()` on a `Result` value
-  --> tests/ui/manual_is_variant_and.rs:119:18
+  --> tests/ui/manual_is_variant_and.rs:57:18
    |
 LL |     let _ = res2.map(char::is_alphanumeric).unwrap_or_default(); // should lint
    |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use: `is_ok_and(char::is_alphanumeric)`
 
-error: aborting due to 15 previous errors
+error: aborting due to 8 previous errors
 
diff --git a/src/tools/clippy/tests/ui/return_and_then.fixed b/src/tools/clippy/tests/ui/return_and_then.fixed
index 8d9481d1595..74efa14eeec 100644
--- a/src/tools/clippy/tests/ui/return_and_then.fixed
+++ b/src/tools/clippy/tests/ui/return_and_then.fixed
@@ -67,60 +67,8 @@ fn main() {
             .first() // creates temporary reference
             .and_then(|x| test_opt_block(Some(*x)))
     }
-
-    fn in_closure() -> bool {
-        let _ = || {
-            let x = Some("")?;
-            if x.len() > 2 { Some(3) } else { None }
-            //~^ return_and_then
-        };
-        true
-    }
-
-    fn with_return(shortcut: bool) -> Option<i32> {
-        if shortcut {
-            return {
-                let x = Some("")?;
-                if x.len() > 2 { Some(3) } else { None }
-            };
-            //~^ return_and_then
-        };
-        None
-    }
-
-    fn with_return_multiline(shortcut: bool) -> Option<i32> {
-        if shortcut {
-            return {
-                let mut x = Some("")?;
-                let x = format!("{x}.");
-                if x.len() > 2 { Some(3) } else { None }
-            };
-            //~^^^^ return_and_then
-        };
-        None
-    }
 }
 
 fn gen_option(n: i32) -> Option<i32> {
     Some(n)
 }
-
-mod issue14781 {
-    fn foo(_: &str, _: (u32, u32)) -> Result<(u32, u32), ()> {
-        Ok((1, 1))
-    }
-
-    fn bug(_: Option<&str>) -> Result<(), ()> {
-        let year: Option<&str> = None;
-        let month: Option<&str> = None;
-        let day: Option<&str> = None;
-
-        let _day = if let (Some(year), Some(month)) = (year, month) {
-            day.and_then(|day| foo(day, (1, 31)).ok())
-        } else {
-            None
-        };
-
-        Ok(())
-    }
-}
diff --git a/src/tools/clippy/tests/ui/return_and_then.rs b/src/tools/clippy/tests/ui/return_and_then.rs
index beada921a91..188dc57e588 100644
--- a/src/tools/clippy/tests/ui/return_and_then.rs
+++ b/src/tools/clippy/tests/ui/return_and_then.rs
@@ -63,55 +63,8 @@ fn main() {
             .first() // creates temporary reference
             .and_then(|x| test_opt_block(Some(*x)))
     }
-
-    fn in_closure() -> bool {
-        let _ = || {
-            Some("").and_then(|x| if x.len() > 2 { Some(3) } else { None })
-            //~^ return_and_then
-        };
-        true
-    }
-
-    fn with_return(shortcut: bool) -> Option<i32> {
-        if shortcut {
-            return Some("").and_then(|x| if x.len() > 2 { Some(3) } else { None });
-            //~^ return_and_then
-        };
-        None
-    }
-
-    fn with_return_multiline(shortcut: bool) -> Option<i32> {
-        if shortcut {
-            return Some("").and_then(|mut x| {
-                let x = format!("{x}.");
-                if x.len() > 2 { Some(3) } else { None }
-            });
-            //~^^^^ return_and_then
-        };
-        None
-    }
 }
 
 fn gen_option(n: i32) -> Option<i32> {
     Some(n)
 }
-
-mod issue14781 {
-    fn foo(_: &str, _: (u32, u32)) -> Result<(u32, u32), ()> {
-        Ok((1, 1))
-    }
-
-    fn bug(_: Option<&str>) -> Result<(), ()> {
-        let year: Option<&str> = None;
-        let month: Option<&str> = None;
-        let day: Option<&str> = None;
-
-        let _day = if let (Some(year), Some(month)) = (year, month) {
-            day.and_then(|day| foo(day, (1, 31)).ok())
-        } else {
-            None
-        };
-
-        Ok(())
-    }
-}
diff --git a/src/tools/clippy/tests/ui/return_and_then.stderr b/src/tools/clippy/tests/ui/return_and_then.stderr
index 5feca882860..a7acbe7b340 100644
--- a/src/tools/clippy/tests/ui/return_and_then.stderr
+++ b/src/tools/clippy/tests/ui/return_and_then.stderr
@@ -101,50 +101,5 @@ LL +         })?;
 LL +         if x.len() > 2 { Some(3) } else { None }
    |
 
-error: use the `?` operator instead of an `and_then` call
-  --> tests/ui/return_and_then.rs:69:13
-   |
-LL |             Some("").and_then(|x| if x.len() > 2 { Some(3) } else { None })
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-help: try
-   |
-LL ~             let x = Some("")?;
-LL +             if x.len() > 2 { Some(3) } else { None }
-   |
-
-error: use the `?` operator instead of an `and_then` call
-  --> tests/ui/return_and_then.rs:77:20
-   |
-LL |             return Some("").and_then(|x| if x.len() > 2 { Some(3) } else { None });
-   |                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-help: try
-   |
-LL ~             return {
-LL +                 let x = Some("")?;
-LL +                 if x.len() > 2 { Some(3) } else { None }
-LL ~             };
-   |
-
-error: use the `?` operator instead of an `and_then` call
-  --> tests/ui/return_and_then.rs:85:20
-   |
-LL |               return Some("").and_then(|mut x| {
-   |  ____________________^
-LL | |                 let x = format!("{x}.");
-LL | |                 if x.len() > 2 { Some(3) } else { None }
-LL | |             });
-   | |______________^
-   |
-help: try
-   |
-LL ~             return {
-LL +                 let mut x = Some("")?;
-LL +                 let x = format!("{x}.");
-LL +                 if x.len() > 2 { Some(3) } else { None }
-LL ~             };
-   |
-
-error: aborting due to 10 previous errors
+error: aborting due to 7 previous errors
 
diff --git a/src/tools/clippy/tests/ui/swap_with_temporary.fixed b/src/tools/clippy/tests/ui/swap_with_temporary.fixed
index 4007d998ba0..24c667dd479 100644
--- a/src/tools/clippy/tests/ui/swap_with_temporary.fixed
+++ b/src/tools/clippy/tests/ui/swap_with_temporary.fixed
@@ -72,3 +72,49 @@ fn dont_lint_those(s: &mut S, v: &mut [String], w: Option<&mut String>) {
     swap(&mut s.t, v.get_mut(0).unwrap());
     swap(w.unwrap(), &mut s.t);
 }
+
+fn issue15166() {
+    use std::sync::Mutex;
+
+    struct A {
+        thing: Mutex<Vec<u8>>,
+    }
+
+    impl A {
+        fn a(&self) {
+            let mut new_vec = vec![42];
+            // Do not lint here, as neither `new_vec` nor the result of `.lock().unwrap()` are temporaries
+            swap(&mut new_vec, &mut self.thing.lock().unwrap());
+            for v in new_vec {
+                // Do something with v
+            }
+            // Here `vec![42]` is temporary though, and a proper dereference will have to be used in the fix
+            *self.thing.lock().unwrap() = vec![42];
+            //~^ ERROR: swapping with a temporary value is inefficient
+        }
+    }
+}
+
+fn multiple_deref() {
+    let mut v1 = &mut &mut &mut vec![42];
+    ***v1 = vec![];
+    //~^ ERROR: swapping with a temporary value is inefficient
+
+    struct Wrapper<T: ?Sized>(T);
+    impl<T: ?Sized> std::ops::Deref for Wrapper<T> {
+        type Target = T;
+        fn deref(&self) -> &Self::Target {
+            &self.0
+        }
+    }
+    impl<T: ?Sized> std::ops::DerefMut for Wrapper<T> {
+        fn deref_mut(&mut self) -> &mut Self::Target {
+            &mut self.0
+        }
+    }
+
+    use std::sync::Mutex;
+    let mut v1 = Mutex::new(Wrapper(Wrapper(vec![42])));
+    *(*(*v1.lock().unwrap())) = vec![];
+    //~^ ERROR: swapping with a temporary value is inefficient
+}
diff --git a/src/tools/clippy/tests/ui/swap_with_temporary.rs b/src/tools/clippy/tests/ui/swap_with_temporary.rs
index d403c086c0f..8e35e6144d9 100644
--- a/src/tools/clippy/tests/ui/swap_with_temporary.rs
+++ b/src/tools/clippy/tests/ui/swap_with_temporary.rs
@@ -72,3 +72,49 @@ fn dont_lint_those(s: &mut S, v: &mut [String], w: Option<&mut String>) {
     swap(&mut s.t, v.get_mut(0).unwrap());
     swap(w.unwrap(), &mut s.t);
 }
+
+fn issue15166() {
+    use std::sync::Mutex;
+
+    struct A {
+        thing: Mutex<Vec<u8>>,
+    }
+
+    impl A {
+        fn a(&self) {
+            let mut new_vec = vec![42];
+            // Do not lint here, as neither `new_vec` nor the result of `.lock().unwrap()` are temporaries
+            swap(&mut new_vec, &mut self.thing.lock().unwrap());
+            for v in new_vec {
+                // Do something with v
+            }
+            // Here `vec![42]` is temporary though, and a proper dereference will have to be used in the fix
+            swap(&mut vec![42], &mut self.thing.lock().unwrap());
+            //~^ ERROR: swapping with a temporary value is inefficient
+        }
+    }
+}
+
+fn multiple_deref() {
+    let mut v1 = &mut &mut &mut vec![42];
+    swap(&mut ***v1, &mut vec![]);
+    //~^ ERROR: swapping with a temporary value is inefficient
+
+    struct Wrapper<T: ?Sized>(T);
+    impl<T: ?Sized> std::ops::Deref for Wrapper<T> {
+        type Target = T;
+        fn deref(&self) -> &Self::Target {
+            &self.0
+        }
+    }
+    impl<T: ?Sized> std::ops::DerefMut for Wrapper<T> {
+        fn deref_mut(&mut self) -> &mut Self::Target {
+            &mut self.0
+        }
+    }
+
+    use std::sync::Mutex;
+    let mut v1 = Mutex::new(Wrapper(Wrapper(vec![42])));
+    swap(&mut vec![], &mut v1.lock().unwrap());
+    //~^ ERROR: swapping with a temporary value is inefficient
+}
diff --git a/src/tools/clippy/tests/ui/swap_with_temporary.stderr b/src/tools/clippy/tests/ui/swap_with_temporary.stderr
index 59355771a96..c0ea592fb05 100644
--- a/src/tools/clippy/tests/ui/swap_with_temporary.stderr
+++ b/src/tools/clippy/tests/ui/swap_with_temporary.stderr
@@ -96,5 +96,41 @@ note: this expression returns a temporary value
 LL |     swap(mac!(refmut y), &mut func());
    |                               ^^^^^^
 
-error: aborting due to 8 previous errors
+error: swapping with a temporary value is inefficient
+  --> tests/ui/swap_with_temporary.rs:92:13
+   |
+LL |             swap(&mut vec![42], &mut self.thing.lock().unwrap());
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use assignment instead: `*self.thing.lock().unwrap() = vec![42]`
+   |
+note: this expression returns a temporary value
+  --> tests/ui/swap_with_temporary.rs:92:23
+   |
+LL |             swap(&mut vec![42], &mut self.thing.lock().unwrap());
+   |                       ^^^^^^^^
+
+error: swapping with a temporary value is inefficient
+  --> tests/ui/swap_with_temporary.rs:100:5
+   |
+LL |     swap(&mut ***v1, &mut vec![]);
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use assignment instead: `***v1 = vec![]`
+   |
+note: this expression returns a temporary value
+  --> tests/ui/swap_with_temporary.rs:100:27
+   |
+LL |     swap(&mut ***v1, &mut vec![]);
+   |                           ^^^^^^
+
+error: swapping with a temporary value is inefficient
+  --> tests/ui/swap_with_temporary.rs:118:5
+   |
+LL |     swap(&mut vec![], &mut v1.lock().unwrap());
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use assignment instead: `*(*(*v1.lock().unwrap())) = vec![]`
+   |
+note: this expression returns a temporary value
+  --> tests/ui/swap_with_temporary.rs:118:15
+   |
+LL |     swap(&mut vec![], &mut v1.lock().unwrap());
+   |               ^^^^^^
+
+error: aborting due to 11 previous errors
 
diff --git a/tests/rustdoc/constant/const-trait-and-impl-methods.rs b/tests/rustdoc/constant/const-trait-and-impl-methods.rs
new file mode 100644
index 00000000000..30fc539e553
--- /dev/null
+++ b/tests/rustdoc/constant/const-trait-and-impl-methods.rs
@@ -0,0 +1,36 @@
+// check that we don't render `#[const_trait]` methods as `const` - even for
+// const `trait`s and `impl`s.
+#![crate_name = "foo"]
+#![feature(const_trait_impl)]
+
+//@ has foo/trait.Tr.html
+//@ has - '//*[@id="tymethod.required"]' 'fn required()'
+//@ !has - '//*[@id="tymethod.required"]' 'const'
+//@ has - '//*[@id="method.defaulted"]' 'fn defaulted()'
+//@ !has - '//*[@id="method.defaulted"]' 'const'
+#[const_trait]
+pub trait Tr {
+    fn required();
+    fn defaulted() {}
+}
+
+pub struct ConstImpl {}
+pub struct NonConstImpl {}
+
+//@ has foo/struct.ConstImpl.html
+//@ has - '//*[@id="method.required"]' 'fn required()'
+//@ !has - '//*[@id="method.required"]' 'const'
+//@ has - '//*[@id="method.defaulted"]' 'fn defaulted()'
+//@ !has - '//*[@id="method.defaulted"]' 'const'
+impl const Tr for ConstImpl {
+    fn required() {}
+}
+
+//@ has foo/struct.NonConstImpl.html
+//@ has - '//*[@id="method.required"]' 'fn required()'
+//@ !has - '//*[@id="method.required"]' 'const'
+//@ has - '//*[@id="method.defaulted"]' 'fn defaulted()'
+//@ !has - '//*[@id="method.defaulted"]' 'const'
+impl Tr for NonConstImpl {
+    fn required() {}
+}
diff --git a/tests/ui/runtime/out-of-stack.rs b/tests/ui/runtime/out-of-stack.rs
index 6be34afb560..913d3637c8f 100644
--- a/tests/ui/runtime/out-of-stack.rs
+++ b/tests/ui/runtime/out-of-stack.rs
@@ -19,7 +19,7 @@ extern crate libc;
 use std::env;
 use std::hint::black_box;
 use std::process::Command;
-use std::thread;
+use std::thread::Builder;
 
 fn silent_recurse() {
     let buf = [0u8; 1000];
@@ -56,9 +56,9 @@ fn main() {
     } else if args.len() > 1 && args[1] == "loud" {
         loud_recurse();
     } else if args.len() > 1 && args[1] == "silent-thread" {
-        thread::spawn(silent_recurse).join();
+        Builder::new().name("ferris".to_string()).spawn(silent_recurse).unwrap().join();
     } else if args.len() > 1 && args[1] == "loud-thread" {
-        thread::spawn(loud_recurse).join();
+        Builder::new().name("ferris".to_string()).spawn(loud_recurse).unwrap().join();
     } else {
         let mut modes = vec![
             "silent-thread",
@@ -82,6 +82,12 @@ fn main() {
             let error = String::from_utf8_lossy(&silent.stderr);
             assert!(error.contains("has overflowed its stack"),
                     "missing overflow message: {}", error);
+
+            if mode.contains("thread") {
+                assert!(error.contains("ferris"), "missing thread name: {}", error);
+            } else {
+                assert!(error.contains("main"), "missing thread name: {}", error);
+            }
         }
     }
 }